fixes #1942 - added a custom call for calling any manually set OnTouchListeners (#2703)

Xamarin.Forms.ControlGallery.Android/CustomRenderers.cs

@@ -17,12 +17,15 @@ using Android.Runtime;
 using Android.Util;
 using AButton = Android.Widget.Button;
 using AView = Android.Views.View;
+using AViewGroup = Android.Views.ViewGroup;
 using Android.OS;
 using System.Reflection;
 using Android.Text;
 using Android.Text.Method;
 using Xamarin.Forms.Controls.Issues;
 
+
+[assembly: ExportRenderer(typeof(Issue1942.CustomGrid), typeof(Issue1942GridRenderer))]
 [assembly: ExportRenderer(typeof(Bugzilla31395.CustomContentView), typeof(CustomContentRenderer))]
 [assembly: ExportRenderer(typeof(NativeListView), typeof(NativeListViewRenderer))]
 [assembly: ExportRenderer(typeof(NativeListView2), typeof(NativeAndroidListViewRenderer))]
@@ -605,6 +608,49 @@ namespace Xamarin.Forms.ControlGallery.Android
 		}
 	}
 
+	public class Issue1942GridRenderer : VisualElementRenderer<Grid>, AView.IOnTouchListener, ViewTreeObserver.IOnGlobalLayoutListener
+	{
+		AView _gridChild;
+		public Issue1942GridRenderer(Context context) : base(context)
+		{
+		}
+
+		bool AView.IOnTouchListener.OnTouch(AView v, MotionEvent e)
+		{
+			((Element.Children.First() as Layout).Children.First() as Label).Text = Issue1942.SuccessString;
+			ViewGroup.ViewTreeObserver.RemoveOnGlobalLayoutListener(this);
+			_gridChild.SetOnTouchListener(null);
+			return true;
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<Grid> e)
+		{
+			base.OnElementChanged(e);
+			if (e.NewElement != null)
+			{
+				ViewGroup.ViewTreeObserver.AddOnGlobalLayoutListener(this);
+			}
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if(disposing)
+			{
+				ViewGroup.ViewTreeObserver.RemoveOnGlobalLayoutListener(this);
+				_gridChild.SetOnTouchListener(null);
+				_gridChild = null;
+			}
+
+			base.Dispose(disposing);
+		}
+
+		void ViewTreeObserver.IOnGlobalLayoutListener.OnGlobalLayout()
+		{
+			_gridChild = ViewGroup.GetChildAt(0);
+			_gridChild.SetOnTouchListener(this);
+		}
+	}
+
 	public static class KeyboardFlagExtensions
 	{
 		public static void TestKeyboardFlags(this FormsEditText Control, KeyboardFlags? flags)

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue1942.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 1942, "[Android] Attached Touch Listener events do not dispatch to immediate parent Grid Renderer View on Android when Child fakes handled",
+		PlatformAffected.Android)]
+	public class Issue1942 : TestContentPage
+	{
+		public const string SuccessString = "Success";
+		public const string ClickMeString = "CLICK ME";
+
+		protected override void Init()
+		{
+			Content = new CustomGrid()
+			{
+				Children =
+				{
+					new Grid
+					{
+						Children = { new Label() { Text = ClickMeString, BackgroundColor = Color.Blue, HeightRequest = 300, WidthRequest = 300 } }
+					}
+				}
+			};
+		}
+
+		public class CustomGrid : Grid { }
+
+#if UITEST && __ANDROID__
+		[Test]
+		public void ClickPropagatesToOnTouchListener()
+		{
+			RunningApp.Tap(ClickMeString);
+			RunningApp.WaitForElement(SuccessString);
+		}
+#endif
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -249,6 +249,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue1705_2.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1396.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1415.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue1942.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue2247.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)GroupListViewHeaderIndexOutOfRange.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1760.cs" />

Xamarin.Forms.Platform.Android/Platform.cs

@@ -65,7 +65,7 @@ namespace Xamarin.Forms.Platform.Android
 			{
 				_defaultActionBarTitleTextColor = SetDefaultActionBarTitleTextColor();
 			}
-			
+
 			_renderer = new PlatformRenderer(context, this);
 
 			if (embedded)
@@ -1105,8 +1105,8 @@ namespace Xamarin.Forms.Platform.Android
 		static int s_id = 0x00000400;
 
 		#region Previewer Stuff
-		
-		internal static readonly BindableProperty PageContextProperty = 
+
+		internal static readonly BindableProperty PageContextProperty =
 			BindableProperty.CreateAttached("PageContext", typeof(Context), typeof(Platform), null);
 
 		internal Platform(Context context) : this(context, false)
@@ -1115,12 +1115,12 @@ namespace Xamarin.Forms.Platform.Android
 			// the 'embedded' bool parameter so the previewer can find it via reflection
 		}
 
-		internal static void SetPageContext(BindableObject bindable, Context context)		
- 		{
+		internal static void SetPageContext(BindableObject bindable, Context context)
+		{
 			// Set a context for this page and its child controls
 			bindable.SetValue(PageContextProperty, context);
 		}
-		
+
 		static Context GetPreviewerContext(Element element)
 		{
 			// Walk up the tree and find the Page this element is hosted in
@@ -1139,6 +1139,7 @@ namespace Xamarin.Forms.Platform.Android
 		internal class DefaultRenderer : VisualElementRenderer<View>
 		{
 			bool _notReallyHandled;
+			IOnTouchListener _touchListener;
 
 			[Obsolete("This constructor is obsolete as of version 2.5. Please use DefaultRenderer(Context) instead.")]
 			public DefaultRenderer()
@@ -1207,11 +1208,29 @@ namespace Xamarin.Forms.Platform.Android
 					// don't consider the event truly "handled" yet. 
 					// Since a child control short-circuited the normal dispatchTouchEvent stuff, this layout never got the chance for
 					// IOnTouchListener.OnTouch and the OnTouchEvent override to try handling the touches; we'll do that now
-					return OnTouchEvent(e);
+					// Any associated Touch Listeners are called from DispatchTouchEvents if all children of this view return false
+					// So here we are simulating both calls that would have typically been called from inside DispatchTouchEvent
+					// but were not called due to the fake "true"
+					result = _touchListener?.OnTouch(this, e) ?? false;
+					return result || OnTouchEvent(e);
 				}
 
 				return result;
 			}
+
+			public override void SetOnTouchListener(IOnTouchListener l)
+			{
+				_touchListener = l;
+				base.SetOnTouchListener(l);
+			}
+
+			protected override void Dispose(bool disposing)
+			{
+				if (disposing)
+					_touchListener = null;
+
+				base.Dispose(disposing);
+			}
 		}
 
 		#region IPlatformEngine implementation